Remove six and python 2.7 full support

Six is in use to help us to keep support for python 2.7.
Since the ussuri cycle we decide to remove the python 2.7
support so we can go ahead and also remove six usage from
the python code.

Review process and help
-----------------------
Removing six introduce a lot of changes and an huge amount of modified files
To simplify reviews we decided to split changes into several patches to avoid
painful reviews and avoid mistakes.

To review this patch you can use the six documentation [1] to obtain help and
understand choices.

Additional informations
-----------------------
Changes related to 'six.b(data)' [2]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

six.b [2] encode the given datas in latin-1 in python3 so I did the same
things in this patch.

Latin-1 is equal to iso-8859-1 [3].

This encoding is the default encoding [4] of certain descriptive HTTP
headers.

I suggest to keep latin-1 for the moment and to move to another encoding
in a follow-up patch if needed to move to most powerful encoding (utf8).

HTML4 support utf8 charset and utf8 is the default charset for HTML5 [5].

Note that this commit message is autogenerated and not necesserly contains
changes related to 'six.b'

[1] https://six.readthedocs.io/
[2] https://six.readthedocs.io/#six.b
[3] https://docs.python.org/3/library/codecs.html#standard-encodings
[4] https://www.w3schools.com/charsets/ref_html_8859.asp
[5] https://www.w3schools.com/html/html_charset.asp

Patch 28 of a serie of 28 patches
six fully removed now!
Thank you six for the rendered services!

Change-Id: If44ee4b565cc9390fa0422fba4dda080b4f90b98

1 files changed, 3 insertions, 4 deletions

diff --git a/tools/custom_guidelines.py b/tools/custom_guidelines.py
index 3e8f4e2c7..53306d0cc 100644
--- a/tools/custom_guidelines.py
+++ b/tools/custom_guidelines.py
@@ -16,7 +16,6 @@ import re
 import sys
 
 from oslo_log import log
-import six
 
 from heat.common.i18n import _
 from heat.engine import constraints
@@ -101,7 +100,7 @@ class HeatCustomGuidelines(object):
 
     def _check_resource_schemas(self, resource, schema, schema_name,
                                 error_path=None):
-        for key, value in six.iteritems(schema):
+        for key, value in schema.items():
             if error_path is None:
                 error_path = [resource.__name__, key]
             else:
@@ -129,7 +128,7 @@ class HeatCustomGuidelines(object):
             error_path.pop()
 
     def _check_resource_methods(self, resource):
-        for method in six.itervalues(resource.__dict__):
+        for method in resource.__dict__.values():
             # need to skip non-functions attributes
             if not callable(method):
                 continue
@@ -159,7 +158,7 @@ class HeatCustomGuidelines(object):
                 cls_file = open(cls.__module__.replace('.', '/') + '.py')
             except IOError as ex:
                 LOG.warning('Cannot perform trailing spaces check on '
-                            'resource module: %s', six.text_type(ex))
+                            'resource module: %s', str(ex))
                 continue
             lines = [line.strip() for line in cls_file.readlines()]
             idx = 0